1. Field of the Invention
The present invention relates to an apparatus and method for interaction among devices supporting Near Field Communication (NFC). More particularly, the present invention relates to an apparatus and method for power state transitions via NFC.
2. Description of the Related Art
Mobile terminals are developed to provide wireless communication between users. As technology has advanced, mobile terminals now provide many additional features beyond simple telephone conversation. For example, mobile terminals are now able to provide additional functions such as an alarm, a Short Messaging Service (SMS), a Multimedia Message Service (MMS), E-mail, games, remote control of short range communication, an image capturing function using a mounted digital camera, a multimedia function for providing audio and video content, a scheduling function, and many more. With the plurality of features now provided, a mobile terminal has effectively become a necessity of daily life.
In a similar vein, features previously associated only with computers have expanded to other devices. For example, televisions and set-top boxes (including video game consoles, cable boxes, and the like) now offer a variety of features beyond their original functionality, including streaming content and Internet access (e.g., web browsing). In addition, tablets, such as the Apple™ iPad™ and Samsung™ Galaxy Tab™, have exploded in popularity in recent years.
Near Field Communication (NFC) is one technology now being included and featured in these devices. NFC supports very short range communication (typically 4 centimeters or less) between devices. NFC supports both active communication, in which both devices are powered, and passive communication, in which one device draws power from the electromagnetic field generated by the other device.
Devices incorporating NFC functionality typically must be in an awakened state before the NFC functionality may be used. This typically requires the user to perform some physical action, such as touching the screen or pressing a button. According to the related art, the NFC circuit is part of a System on Chip (SoC) or an integrated circuit, such that the NFC circuit is only active while power is supplied to the whole chip.
In some systems according to the related art, certain applications may be executed by a mobile device even while the device is in a powered off or sleep state. However, these systems still require the user to perform physical operations on the mobile device to select an application.
Bluetooth technology has also been suggested as a technique for controlling a power on/off or sleep/wake of a device. However, Bluetooth requires a constant power supply and consumes much more power than NFC. In order to use Bluetooth to control power on/off or sleep/wake, the Bluetooth circuit must be supplied with sufficient power while the device is powered off or in the sleep state. Accordingly, there is a need for enhancing power state transitions in mobile devices while reducing power consumption in a mobile terminal.